Focuszng apparatus for lamps



' E. F. WACKWITZ.

FOCUSING APPARATUS FOR LAMPS.

APPLICATION FILED APR. 17, 1919.

i atented Nov. 29, 1921.

JnZ/ehaO Z I Q? Q Ely/NE??? Pmiontcn Hum 22% 1921}.

Serial. Nam 29 5,3031

To aZ/w/mm it may con/M which will he exemplified by the construc- Be it known. this: l llnrqicst I9. ciun h 'Er set forth and the scope of WI'IZ. a citizen of the United i hc zippllc on which will be indicated ing' at "lington Heights in llll J in Eng claims. Middle. and Slate of i In i; vings wherein a number of the invented certain new and .iilPKi' YiUlOUS possihlc BHlbUdlIllQflilS of the invenhirer or lWYll TlCI' worked out foi menu: in l oc 'sing -apgm in humps, lilm 9,12 lim n:--' which tho following is a phi clear, a. l igurc exact specification. .1

This invention rein"- and with regard to cc features izlicreol to mi l erinining the p the ligln, source @218 of the oh pr ride. simple, ins

; a Vl-OW in cross section of a a parabolic reflector anclits sectional i icw taken on the l 'l liooliing' in the direction 2:13'OWS; S is s plan View looking downwardly on the .reflci'or of 1;

cxzcl; relative positions of the filament, of s head-i J: ight pz' ularly for such ligl'ais used on veniclcs. The use of snhstanti lly 1 gs. 5 and 6 are views illustrating still r moclifi *stion of the invention, and

7 and are f'aglncntary iews of arnholi reflectors for ills mechanism for laterally adjusting the (c. (1' c i. ia fin montmy vinw of a modinleuns for rumbling" our, new in: of the invention;

Nor

automobile in G s nmtsrially :n- "g'lit source.

driving 3 11;; now more p irticnlnrly to the light. and at the gin 111150 draw the indicated at 10 a sub ssrious l 1 :is n'obsins i nuraholic inei-al reflector or the 3811 d s b I ism has been pr;ugzticlfily 1'? m2; wholly t "pa- 51!; pros-en connnonly used. in sufion osolveih hv confirm-ling "eflcctors soms lulu ion s. ivy substantially parabolic s reficctor as nearly in the shape 1 in 3 Wlifli; OIl'i; of true szilzijlolic 350211; by using frosted or pin ally opaque front A mooln as .ls j'gossible under present lens. or in various other ways. lnc inostmanufacturing conditions. The reflector 1O important consiLlr-i'ation, however" in arrlvhas its interior surface highly polished and in; at ihc succcssinl use of such devices i. is incasc il and protected by a, metal casto obtain accurate positioning of the light mg ll wlnch latter is equipped wlth a refilnnient with respect to the particular rcinn able door i2. The door 12 consists Ilector W1. 1 which is nrnployed. The merely or mm WlUCh supports a circular pres invention isncsiwnecl so enable transg'i irent slnolcl 13 preferably, of gloss.

one: 31' 10 ad ust lus llglfllt ulmi'zsnt to The Al; rho the reflector there 1s an point or region which the lamp TH spertura Within which is fixed a sleeve 15 i which carries in turn a lamp sockvzqa 16, the

iwi bus-1;; adjustable longitudinally or 4 means of the screw rod adjust inonl. nmcnnnisin shown at 17. The socket 1.6 offers a moans for receiving an electric iihe one which uiil ccc' Has no A notllci' tivo posiiions of lamp 1:5 in the shape of a bayonet joint 19. focal point The lamp of usual construction having a gm} i-h w; 1, filament 5 30 which intended should- 0c- 1 nosition as nearly possible cenrs pact to the focal point 01 the reflector. In theembodiment of shown in Fig. l, perforations 106 in the upper portion of the hector son's to let th s light from the lamp filainsniz penetrate line body of the reflector. A scrcnn is arranged upon a bracket 24 the la-tfcsr being fixed to the outer surface of 110 ilzunentalong U'ther objccis will in part pal- The invc i various features of consi: 'nc loin cc Lions of elomcns and nrrang'sn'ient to the exact focal point one exact focal a i of the reflector.

tion in transverse plane.

-'cations which in the manufacture of the lam 3 and )artioularlv the reflector are given a definite position rcla't rely to the pertorations 21 and in the ctcr and relatively Perforations 21 and may he of any suitable shape and are herein shown as very small circular (punchings. When the lamp '18 is illuminated a small cylindrical beam of light will pass beyond the reflector through each of the openings 21 and 22 and. strike upon the screen By manipulating the adjusting device 17, the lamp bulb and its filament may he moved axially and this movement is given by the operator until such time as the spot on the screen 23 is centrally distributed about tl'ie'irdications or characters on-the screen. in. 3 of the drawings these indications are cros cs. it will he noted that there are three perforations and three indications. Une of. these, for ins once the central one, may serve to determine the correct position or the filament" along the focal axis. The other two will serve to demonstrate Whether the filament is suilicicntly Within the focal axis or Whether it is displaced transversely thereof. Similar. means shown in the drawing for adjusting the filament in a. planetransversely of the focal axis and it is Withinthe of theinvention to prcvide such means There is some flexibility in the bayonet joint and socket arrangement at the rear of the reflector which permitssome displacement and equally as well permits a. slight Increment of the lamp later-. ally to bring the filament into proper pose Such adius.-

'- ment may he had by rotating either or both rods 26 and 27, which are 90 apart about 7 the rellector and cross levers 28 and $29, which give a lateral movement of the socket in the casing fastened to the'rearof the rc- Hector. A combination of both adjustments effects resultant adjustment in any desired lateral direction. it true that there is little uniformity in the position of iila" rncnt with respect to the pins of thela-inp .loulhs which serve to make the bayonet joint.

For this reason if a lamp 'e'burned out and another one substituted the filament may be a considerable fraction of an inch one way or the other from the position of filament in the lamp formerly in place. This lack of uniformity is true in trans 'verse direction as Well. in a longitudinal direction and it is a practical matter necessary to refocus the device eech time a l'amphulb is replaced.

in the modification shown in t a housing 30 is arovi'lcd on the inner surface of the renector. This housing has a,

shown at in the "form of :uaeessi flat bottom portion which 1S perrorateu as indicated 31. The screen 1nount ed in a frame 33 at the front of t'heh'ousing and indications corresponding to those sl-icwn in Fig. at 25 are made upon the screen. In this form of the invention the light from the filament 2O penetrates the housing through the aperture 31 and" is reflected forv-rardly in the ordinary Way by the reflector. if the filament is forwardlv or reari'ardly of thefocal point the.

opei' r may view a. screen fi arranged upon inner surface of the reflector Within the housing. This screen is provided With an indicating cross as shown in Fire. c. 1

l l hile in the embodiments of the invention shown and described herein substantially parabolic reflector is included, the invention is of course adapted to he used with other forms of reflectors. Any reflector adapted to direct light rays in a given direction and having a inain focal point or region would be capable of adventageous use with the focus determining roe-ans of my invention There ere numerous reflectors in present day usage hosed generally on parabolic principles but mod ified to confine the heain to a low level. or to spread the beam an shape and in com hination with these the invention finds particuh y advantageous application in:- ich as it is usual in the construction c lamps for automobile headshchts upon, the accompanying drawing a few embodiments of the invention, it is to be understood, however, that the invention is not 'ed to particular forms, details and ngenicnt of parts described and shown, hut that other forms, details and. arrangement of. parts comprehended by the invention, as do not depart from. the spirit ceive light rays from a focal region and to and the scope of the apv reflect said rays into a beam of light, an

electric filament, means for adjustably supporting the filament in said reflector to bring it into proper position relatively to said reflector, and means comprising a perforation in said reflector, and a screen fixed on said reflector opposite said perforation and adapted to cooperate with light rays passing from said filament through said perforation to said screen to enable an operator to determine the position of said filament relatively to said reflector.

' In a lamp, in combination, a reflector having a focal axis and a focal point lying within said axis, a filament adjustab ly supported in said reflector and adapted to be positioned along said focal axis, a screen on said reflector having an indicator, said reflector being perforated to permit light rays from said sonrce to be transmitted to said screen in definite relation to said indicator.

3. In a lamp, in combination, a casing, a reflector therein, and shaped to project light in concentrated form, an electric filament adjustably mounted in' said reflector, an optical device forming an integral part of said reflector and adapted to indicate the relative positions of said filament and reflector, and a transparent member in said casing opposite said optical device for per mitting observation of said optical device. 

